Random outcome generators may be used to introduce an element of chance in board games and other games played for entertainment. Dice are probably the most common random outcome generators used for this purpose, although wheels and other devices are also used. A die is a polyhedron that has a number or other indicator imprinted, engraved or otherwise disposed on each of its sides. Each number or indicator is different. When the die is rolled on a flat surface, it comes to rest on one of its sides with another one of its sides facing upward. The number on the upwardly facing side determines the outcome of the roll and is essentially random. Although the most commonly used dice have six sides (hexahedrons or cubes), dice having as many as ten sides (decahedrons), twelve sides (dodecahedrons) or even twenty sides (icosahedrons) are also known.
Dice having a large number of sides are inconvenient to use. The larger the number of sides, the smaller the area of each in relation to the overall size of the die. It is difficult to imprint or engrave numbers or other indicia on very small areas. Furthermore, it is difficult to discern very small indicia. Moreover, the area of the surface on which the die rests must be flat to discern which side is facing upward; the smaller the area of the sides, the flatter the surface must be. Turf, concrete, asphalt, tile and similar rough surfaces are unsuitable for rolling ten or twenty-sided dice of typical size.
Coins have been used to randomly select one of two possible outcomes. Coins are discs having an obverse side and a reverse side, commonly known as a "head" and a "tail," respectively. The head and tail bear different indicia. (The obverse or "head" sides of many coins bear a bust or likeness of a person's head, while the reverse side does not.) When the coin is tossed on a relatively flat surface, it lands with either its obverse or reverse side facing upward. Coins are advantageous because a person can toss a coin of typical size on nearly any surface without experiencing difficulty discerning which side is facing upward. Nevertheless, the use of a coin is limited to generating one of two possible numbers or outcomes. Coins are therefore not used to generate random outcomes in board games and the like.
A game known as "pog" is played using milk-bottle caps or similarly sized discs. The discs, also known as pogs, are stacked on top of one another. The obverse and reverse sides of each pog bear different indicia, and all the pogs are stacked with their obverse sides facing upward. A player tosses another pog, which is sometimes called a "slammer" and which is typically heavier or larger, at the stacked pogs. The stack or a portion of it topples as a result of the impact with the slammer. The player gathers and keeps any pogs that have flipped over, i.e., those that have landed on the ground with their reverse sides up. The remaining pogs are re-stacked, and the player's opponent then takes a turn in the same manner, keeping any pogs that have flipped over. When all pogs have been flipped over, the player with the most pogs wins the game.